Fix broken OIDC Providers link (#11327)

Recent website framework changes don't render pages that aren't linked
from the sidebar. This page has been (for now at least) added to the
sidebar to fix the issue.

website/data/docs-nav-data.json

@@ -1053,8 +1053,17 @@
       },
       {
         "title": "JWT/OIDC",
+        "routes": [
+          {
+            "title": "Overview",
             "path": "auth/jwt"
           },
+          {
+            "title": "OIDC Providers",
+            "path": "auth/jwt_oidc_providers"
+          }
+        ]
+      },
       {
         "title": "Kerberos",
         "path": "auth/kerberos"